U.S. patent application number 12/826308 was filed with the patent office on 2011-01-13 for organic light emitting diode display.
This patent application is currently assigned to Samsung Mobile Display Co., Ltd.. Invention is credited to Beom-Shik Kim, Hui Nam, Chan-Young Park.
Application Number | 20110006327 12/826308 |
Document ID | / |
Family ID | 43426807 |
Filed Date | 2011-01-13 |
United States Patent
Application |
20110006327 |
Kind Code |
A1 |
Park; Chan-Young ; et
al. |
January 13, 2011 |
ORGANIC LIGHT EMITTING DIODE DISPLAY
Abstract
An organic light emitting diode (OLED) display according to an
exemplary embodiment includes a substrate main body, a plurality of
organic light emitting elements formed on the substrate main body,
an encapsulation thin film formed on the substrate main body
thereby covering the plurality of organic light emitting elements,
and a disparity barrier rib layer formed on a boundary region
between the plurality of organic light emitting elements.
Inventors: |
Park; Chan-Young;
(Yongin-City, KR) ; Kim; Beom-Shik; (Yongin-City,
KR) ; Nam; Hui; (Yongin-City, KR) |
Correspondence
Address: |
ROBERT E. BUSHNELL & LAW FIRM
2029 K STREET NW, SUITE 600
WASHINGTON
DC
20006-1004
US
|
Assignee: |
Samsung Mobile Display Co.,
Ltd.
Yongin City
KR
|
Family ID: |
43426807 |
Appl. No.: |
12/826308 |
Filed: |
June 29, 2010 |
Current U.S.
Class: |
257/98 ; 257/40;
257/E33.068; 257/E51.022 |
Current CPC
Class: |
H01L 51/5281 20130101;
H01L 51/5253 20130101; H01L 27/326 20130101; H01L 27/3246 20130101;
H01L 27/3213 20130101 |
Class at
Publication: |
257/98 ; 257/40;
257/E33.068; 257/E51.022 |
International
Class: |
H01L 33/58 20100101
H01L033/58; H01L 51/52 20060101 H01L051/52 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2009 |
KR |
10-2009-0063229 |
Claims
1. An organic light emitting diode (OLED) display comprising: a
substrate main body; a plurality of organic light emitting elements
formed on the substrate main body; an encapsulation thin film
formed on the substrate main body thereby covering the plurality of
organic light emitting elements; and a disparity barrier rib layer
formed in correspondence with a plurality of boundary regions
disposed between the plurality of organic light emitting
elements.
2. The organic light emitting diode (OLED) display of claim 1,
wherein one organic light emitting element among the plurality of
organic light emitting elements emits light of a color different
from the color of the light emitted by at least one among
neighboring organic light emitting elements.
3. The organic light emitting diode (OLED) display of claim 2,
wherein the disparity barrier rib layer generates a disparity of
images formed by the light emitted from the plurality of organic
light emitting elements.
4. The organic light emitting diode (OLED) display of claim 1,
wherein the disparity barrier rib layer is formed of one of an
organic layer and an inorganic layer including a light blocking
component.
5. The organic light emitting diode (OLED) display of claim 1,
wherein the disparity barrier rib layer is separated from the
plurality of organic light emitting elements by a distance in a
range of approximately 0.1 .mu.m to approximately 10 .mu.m.
6. The organic light emitting diode (OLED) display of claim 1,
wherein the encapsulation thin film and the disparity barrier rib
layer are integrally formed.
7. The organic light emitting diode (OLED) display of claim 6,
wherein the encapsulation thin film has a thickness in a range of
approximately 0.1 .mu.m to approximately 10 .mu.m.
8. The organic light emitting diode (OLED) display of claim 6,
wherein the encapsulation thin film has a multi-layer structure in
which a plurality of inorganic layers are deposited.
9. The organic light emitting diode (OLED) display of claim 8,
wherein the inorganic layer is made of a material including at
least one of Al.sub.2O.sub.3, TiO.sub.2, ZrO, SiO.sub.2, AlON, AlN,
SiON, Si.sub.3N.sub.4, ZnO, and Ta.sub.2O.sub.5.
10. The organic light emitting diode (OLED) display of claim 8,
wherein the disparity barrier rib layer is disposed between the
plurality of inorganic layers.
11. The organic light emitting diode (OLED) display of claim 8,
wherein the disparity barrier rib layer is disposed on the highest
layer that is furthermost from the plurality of organic light
emitting elements.
12. The organic light emitting diode (OLED) display of claim 6,
wherein the encapsulation thin film is formed with a multi-layer
structure in which a plurality of inorganic layers and a plurality
of organic layers are alternately deposited.
13. The organic light emitting diode (OLED) display of claim 12,
wherein the inorganic layer is formed of a material including at
least one of Al.sub.2O.sub.3, TiO.sub.2, ZrO, SiO.sub.2, AlON, AlN,
SiON, Si.sub.3N.sub.4, ZnO, and Ta.sub.2O.sub.5, and the organic
layer is made of a material selected from a polymer group.
14. The organic light emitting diode (OLED) display of claim 13,
the polymer group comprises an acryl-based resin, an epoxy group
resin, polyimide, and polyethylene.
15. The organic light emitting diode (OLED) display of claim 12,
wherein the disparity barrier rib layer is disposed between the
plurality of inorganic layers and organic layers.
16. The organic light emitting diode (OLED) display of claim 12,
wherein the disparity barrier rib layer is disposed on the highest
layer that is furthermost from the plurality of organic light
emitting elements.
17. The organic light emitting diode (OLED) display of claim 1,
further comprising a filler layer filling the space where the
disparity barrier rib layer is not formed and being disposed within
the same layer as the disparity barrier rib layer.
Description
CLAIM OF PRIORITY
[0001] This application makes reference to, incorporates into this
specification the entire contents of, and claims all benefits
accruing under 35 U.S.C. .sctn.119 from an application earlier
filed in the Korean Intellectual Property Office on Jul. 10, 2009,
and there duly assigned Serial No. 10-2009-0063229.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The described technology relates generally to an organic
light emitting diode (OLED) display. More particularly, the
described technology relates generally to an organic light emitting
diode (OLED) display displaying a three-dimensional image with high
resolution.
[0004] 2. Description of the Related Art
[0005] An organic light emitting diode (OLED) display has a
self-emissive characteristic, and thus, unlike a liquid crystal
display, does not need a separate light source. Therefore, the OLED
display can be reduced in thickness and weight. In addition, since
the OLED display has high-quality characteristics such as low power
consumption, high luminance, fast reaction time, and the like, the
OLED display is drawing attention as a next generation display
device for a portable electronic device.
[0006] Recently, a requirement for a display device that
realistically represents three-dimensional images has increased. A
three-dimensional image may be displayed through a method in which
images recognized by the left eye and the right eye of a viewer
observing the display device are divided to be shown. That is, the
three-dimensional image may be realized by generating a disparity
for the images represented through the display device.
[0007] Accordingly, to effectively display three-dimensional images
through the organic light emitting diode (OLED) display, a twist
nematic (TN) mode liquid crystal is to disposed on the glass
substrate covering the organic light emitting element, or a barrier
rib is formed on the glass substrate to generate the disparity.
[0008] There is a problem in the configuration using the liquid
crystal in that the transmittance of light is deteriorated in the
process of passing through the liquid crystal layer. Accordingly,
the overall luminance of the organic light emitting diode (OLED)
display is deteriorated. Also, as the size of the organic light
emitting diode (OLED) display is increased, the manufacturing
process of the organic light emitting diode (OLED) display using
the liquid crystal is more complicated and productivity is
decreased. Further, the overall thickness of the organic light
emitting diode (OLED) display becomes excessively thick such that
it is difficult to satisfy the desire of the user for thinness.
[0009] In addition, the configuration including the barrier rib
formed on the glass substrate may have a thinner thickness of the
organic light emitting diode (OLED) display compared with the
configuration using the liquid crystal; however, the thickness of
the barrier rib is added to the thickness of the glass substrate
such that the overall thickness of the organic light emitting diode
(OLED) display is increased.
[0010] Further, according to several conditions such as the total
size of the organic light emitting diode (OLED) display and the
size of a pixel as a minimum unit displaying the image for the
organic light minting diode (OLED) display, the barrier rib must be
separated from the organic light emitting element by a
predetermined interval to effectively form the three-dimensional
image. When the barrier rib is formed on the glass substrate,
however, it is difficult to appropriately control the distance
between the barrier rib and the organic light emitting element.
[0011] The above information disclosed in this Background section
is only for enhancement of understanding of the background of the
described technology and therefore it may contain information that
does not form the prior art that is already known in this country
to a person of ordinary skill in the art.
SUMMARY OF THE INVENTION
[0012] It is therefore an aspect of the present invention to
provide an improved organic light emitting diode display.
[0013] It is another aspect of the present invention to provide an
organic light emitting diode display that can effectively display
three-dimensional images of high resolution, and simultaneously
realize overall slimness.
[0014] An organic light emitting diode (OLED) display according to
an exemplary embodiment includes a substrate main body, a plurality
of organic light emitting elements formed on the substrate main
body, an encapsulation thin film formed on the substrate main body
thereby covering the plurality of organic light emitting elements,
and a disparity barrier rib layer formed on a boundary region
between the plurality of organic light emitting elements.
[0015] One organic light emitting element among the plurality of
organic light emitting elements may emit light of a color different
from the color of the light emitted by at least one among
neighboring organic light emitting elements.
[0016] The disparity barrier rib layer may generate a disparity for
an image formed by light emitted from the plurality of organic
light emitting elements.
[0017] The disparity barrier rib layer may be made of one of an
organic layer and an inorganic layer including a light blocking
component.
[0018] The disparity barrier rib layer may be separated from the
plurality of organic light emitting elements by a distance in a
range of approximately 0.1 .mu.m to 10 .mu.m.
[0019] The encapsulation thin film and the disparity barrier rib
layer may be integrally formed.
[0020] The encapsulation thin film may have a thickness of
approximately 0.1 .mu.m to 10 .mu.M.
[0021] The encapsulation thin film may have a multi-layer structure
in which a plurality of inorganic layers are deposited.
[0022] The inorganic layer may be made of a material including at
least one of Al.sub.2O.sub.3, TiO.sub.2, ZrO, SiO.sub.2, AlON, AlN,
SiON, Si.sub.3N.sub.4, ZnO, and Ta.sub.2O.sub.5.
[0023] The disparity barrier rib layer may be disposed between the
plurality of inorganic layers.
[0024] The disparity barrier rib layer may be disposed on the
highest layer that is furthermost from the plurality of organic
light emitting elements.
[0025] The encapsulation thin film may be formed with a multi-layer
structure in which a plurality of inorganic layers and a plurality
of organic layers are alternately deposited.
[0026] The inorganic layer may be formed of a material including at
least one of Al.sub.2O.sub.3, TiO.sub.2, ZrO, SiO.sub.2, AlON, AlN,
SiON, Si.sub.3N.sub.4, ZnO, and Ta.sub.2O.sub.5, and the organic
layer may be made of a material selected from a polymer group.
[0027] The disparity barrier rib layer may be disposed between the
plurality of inorganic layers and organic layers.
[0028] The disparity barrier rib layer may be disposed on the
highest layer that is furthermost from the plurality of organic
light emitting elements.
[0029] According to the present invention, the organic light
emitting diode (OLED) display may effectively display
three-dimensional images, and may simultaneously the overall
thickness may be small.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] A more complete appreciation of the invention, and many of
the attendant advantages thereof, will be readily apparent as the
same becomes better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings in which like reference symbols indicate the
same or similar components, wherein:
[0031] FIG. 1 is a cross-sectional view of an organic light
emitting diode (OLED) display constructed as a first exemplary
embodiment according to the principles of the present
invention;
[0032] FIG. 2 is a layout view of a pixel circuit in the organic
light emitting diode (OLED) display shown in FIG. 1;
[0033] FIG. 3 is a cross-sectional view taken along the line of
FIG. 2;
[0034] FIG. 4 is a cross-sectional view of an organic light
emitting diode (OLED) display constructed as a second exemplary
embodiment according to the principles of the present invention;
and
[0035] FIG. 5 is a cross-sectional view of an organic light
emitting diode (OLED) display constructed as a third exemplary
embodiment according to the principles of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The present invention will be described more fully
hereinafter with reference to the accompanying drawings, in which
exemplary embodiments of the invention are shown. As those skilled
in the art would realize, the described embodiments may be modified
in various different ways, all without departing from the spirit or
scope of the present invention.
[0037] In the several exemplary embodiments, constituent elements
having the same configuration are representatively described in the
first exemplary embodiment by designating like constituent elements
thereto, and other exemplary embodiments will be described only
regarding differences from the first exemplary embodiment.
[0038] The drawings and description are to be regarded as
illustrative in nature and not restrictive. Like reference numerals
designate like elements throughout the specification.
[0039] In addition, the size and thickness of each element in the
drawings are random samples for better understanding and ease of
description, and the present invention is not limited thereto.
[0040] In the drawings, the thickness of layers, films, panels,
regions, etc., are exaggerated for clarity and better understanding
and ease of description. It will be understood that when an element
such as a layer, film, region, or substrate is referred to as being
"on" another element, it can be directly on the other element or
intervening elements may also be present. In contrast, when an
element is referred to as being "directly on" another element,
there are no intervening elements present.
[0041] Now, a first exemplary embodiment will be described with
reference to FIG. 1 to FIG. 3.
[0042] As shown in FIG. 1, an organic light emitting diode (OLED)
display 101 constructed as the first exemplary embodiment according
to the principles of the present invention includes a display
substrate 110, an encapsulation thin film 210, and a disparity
barrier rib layer 220.
[0043] Display substrate 110 includes a substrate main body 111, a
driving circuit unit DC, and an organic light emitting element 70
formed on substrate main body 111. Organic light emitting element
70 displays visual images with an organic emission layer 720 (shown
in FIG. 3) that emits light, and driving circuit unit DC drives
organic light emitting element 70. Structures of organic light
emitting element 70 and driving circuit unit DC are not limited to
the structures shown in FIG. 1 to FIG. 3, and they may be variously
modified within a range that can be easily realized by a person
skilled in the art according to a direction of a visual image
displayed by the light emitted from organic light emitting element
70.
[0044] Also, organic light emitting diode (OLED) display 101
displays visual images through a plurality of pixels. Here, a pixel
is a minimum unit for displaying an image. Also, a plurality of
organic light emitting elements 70 are formed for each pixel in
display substrate 110.
[0045] One organic light emitting element 70b of a plurality of
organic light emitting elements 70 emits light of a color different
from the color of the light emitted by at least one of neighboring
organic light emitting elements 70a and 70c. That is, organic light
emitting elements 70a, 70b, and 70c emitting light of different
colors may be alternatively arranged according to at least one of a
column direction and a row direction. In an embodiment constructed
according to the principles of the present invention, among
plurality of organic light emitting elements 70 illustrated in FIG.
1, organic light emitting element 70a emits red light; organic
light emitting element 70b emits green light; organic light
emitting element 70c emits blue light; and organic light emitting
elements 70a, 70b and 70c are arranged in the row direction.
[0046] Encapsulation thin film 210 is formed with a multi-layer
structure including a plurality of inorganic layers 211, 212, 213,
and 214. Here, inorganic layers 211, 212, 213, and 214 are made of
a material including at least one of Al.sub.2O.sub.3, TiO.sub.2,
ZrO, SiO.sub.2, AlON, AlN, SiON, Si.sub.3N.sub.4, ZnO, and
Ta.sub.2O.sub.5.
[0047] Encapsulation thin film 210 protects organic light emitting
element 70 by preventing moisture or oxygen from penetrating into
organic light emitting element 70. Encapsulation thin film 210 must
satisfy a water vapor transmission rate (WVTR) condition of less
than 10E-6 g/m.sup.2/day that is generally required for an organic
light emitting diode (OLED) display.
[0048] Also, in FIG. 1, encapsulation thin film 210 is formed of
four inorganic layers 211, 212, 213, and 214. The first exemplary
embodiment is, however, not limited thereto. Accordingly,
encapsulation thin film 210 may be variously formed of two or more
inorganic layers, as necessary.
[0049] Disparity barrier rib layer 220 is formed on a boundary
region between the plurality of organic light emitting elements 70.
That is, disparity barrier rib layer 220 includes a plurality of
barrier ribs, and each barrier rib is disposed corresponding to a
boundary region between two immediately adjacent organic light
emitting elements 70. Also, disparity barrier rib layer 220
generates a disparity of images formed by the light emitted from
organic light emitting elements 70. The images displayed by organic
light emitting diode (OLED) display 101 have the disparity
generated by disparity barrier rib layer 220. In this way, a user
that views organic light emitting diode (OLED) display 101
constructed with disparity barrier rib layer 220 respectively
recognizes images that are divided into the left eye and the right
eye of the user. Accordingly, organic light emitting diode (OLED)
display 101 may provide three-dimensional images to the user. That
is, an image is spatially separated by disparity barrier rib layer
220 into an image received by a left eye of a user (hereinafter
referred to as a "left-eye image") and an image received by a right
eye of the user (hereinafter referred to as a "right-eye image"),
and therefore the user can receive the left-eye image and the
right-eye image to recognize a three-dimensional image.
[0050] Disparity barrier rib layer 220 may be made of an organic
layer or an inorganic layer including a light blocking component.
That is, disparity barrier rib layer 220 may be formed of an
organic material including a pigment such as carbon black or
titanium oxide, to or an inorganic material including chromium,
chromium oxide, chromium nitride, or other metal oxides.
[0051] To generate an appropriate disparity by disparity barrier
rib layer 220, the plurality of organic light emitting elements 70
are separated from each other by a distance in a predetermined
range. Herein, the predetermined range is equal to or more than 0.1
.mu.m and equal to or less than 10 .mu.m. If the distance between
disparity barrier rib layer 220 and organic light emitting elements
70 is less than 0.1 .mu.m, it is difficult for disparity barrier
rib layer 220 to generate the appropriate disparity. On the other
hand, if the distance between disparity barrier rib layer 220 and
organic light emitting elements 70 is more than 10 .mu.m, the
overall thickness of organic light emitting diode (OLED) display
101 is significantly increased. Accordingly, the distance between
disparity barrier rib layer 220 and organic light emitting elements
70 is in the range of 0.1 .mu.m to 10 .mu.m, and has an appropriate
length when considering the overall size of organic light emitting
diode (OLED) display 101 and the size of the pixel.
[0052] Also, as shown in FIG. 1, in the first exemplary embodiment,
disparity barrier rib layer 220 is integrally formed with
encapsulation thin film 210. Disparity barrier rib layer 220 is,
however, not necessarily integrally formed with encapsulation thin
film 210, and disparity barrier rib layer 220 may be separately
formed from encapsulation thin film 210.
[0053] Disparity barrier rib layer 220 is disposed between the
several inorganic layers 211, 212, 213, and 214 of encapsulation
thin film 210. That is, disparity barrier rib layer 220 is formed
in the process of forming the several inorganic layers 211, 212,
213, and 214 of encapsulation thin film 210, and finally disparity
barrier rib layer 220 and encapsulation thin film 210 are completed
together. Under consideration of the distance between disparity
barrier rib layer 220 and organic light emitting element 70, it may
be determined whether disparity barrier rib layer 220 is formed
between some inorganic layers 212 and 213 among the several
inorganic layers 211, 212, 213, and 214 of encapsulation thin film
210. That is, the distance between disparity barrier rib layer 220
and organic light emitting elements 70 may be controlled if
necessary.
[0054] Also, encapsulation thin film 210 that is integrally formed
with disparity barrier rib layer 220 has an overall thickness that
is inside the range of 0.1 .mu.m to 10 .mu.m. Accordingly, the
distance between disparity barrier rib layer 220 and organic light
emitting elements 70 may also be controlled inside the range of 0.1
.mu.m to 10 .mu.m. If the entire thickness of encapsulation thin
film 210 is less than 0.1 .mu.m, it is difficult to satisfy the
water vapor transmission rate (WVTR) condition of less than 10E-6
g/m.sup.2/day that is generally required in organic light emitting
diode (OLED) display 101; and if the entire thickness is more than
10 .mu.m, the overall thickness of organic light emitting diode
(OLED) display 101 is increased.
[0055] By this configuration, organic light emitting diode (OLED)
display 101 constructed as the first exemplary embodiment according
to the principles of the present invention may effectively display
three-dimensional images and may simultaneously reduce the entire
thickness.
[0056] That is, organic light emitting diode (OLED) display 101 may
display the image to be divided to the user to be shown through the
left eye and the right eye. Also, organic light emitting element 70
is covered by encapsulation thin film 210, and the entire thickness
of organic light emitting diode (OLED) display 101 may be slim.
[0057] In addition, the separation distance of disparity barrier
rib layer 220 forming the disparity from organic light emitting
element 70 may be easily controlled. That is, according to the
entire size of organic light emitting diode (OLED) display 101 or
the size of the pixel included in organic light emitting diode
(OLED) display 101, the position of disparity barrier rib layer 220
may be controlled to form an appropriate disparity.
[0058] Next, an internal structure of organic light emitting diode
(OLED) display 101 will be described with reference to FIG. 2 and
FIG. 3. FIG. 2 is a layout view of a pixel circuit in the organic
light emitting diode (OLED) display shown in FIG. 1, and FIG. 3 is
a cross-sectional view of display substrate 110 and encapsulation
thin film 210 taken along the line III-III of FIG. 2.
[0059] As shown in FIG. 2 and FIG. 3, display substrate 110
includes a switching thin film transistor 10, a driving thin film
transistor 20, a capacitor 80, and an organic light emitting
element 70 in each pixel. Here, the configuration including
switching thin film transistor 10, driving thin film transistor 20,
and capacitor 80 is referred to as a driving circuit DC. Also,
display substrate 110 further includes gate lines 151 disposed
along one direction, data lines 171 intersecting and electrically
insulated from gate lines 151, and a common power line 172. Here,
one pixel may be defined by gate line 151, data line 171, and
common power line 172, but the present invention is not necessarily
limited thereto.
[0060] Organic light emitting element 70 includes a pixel electrode
710, an organic emission layer 720 formed on pixel electrode 710,
and a common electrode 730 formed on organic emission layer 720.
Here, pixel electrode 710 is a positive (+) electrode or anode
being a hole injection electrode, and common electrode 730 is a
negative (-) electrode or cathode being an electron injection
electrode. The present invention is, however, not necessarily
limited thereto, and depending upon the driving method of organic
light emitting diode display 100, pixel electrode 710 may be a
cathode, and common electrode 730 may be an anode. Holes and
electrons are injected from pixel electrode 710 and common
electrode 730 into organic emissive layer 720. When excitons, which
are the combinations of the injected holes and electrons, shift
from the excited state to the ground state, light is emitted.
[0061] Furthermore, with an organic light emitting diode display
according to the first exemplary embodiment, organic light emitting
diode 70 emits light in the direction of encapsulation substrate
210. That is, organic light emitting diode display 100 is a front
emission type. Here, for organic light emitting element 70 to emit
the light in the direction of encapsulation substrate 210, pixel
electrode 710 is used as a reflective electrode, and common
electrode 730 is used as a transmissive or translucent
electrode.
[0062] Capacitor 80 has a pair of capacitor electrode plates 158
and 178, and an interlayer insulating layer 160 interposed between
two capacitor electrode plates 158 and 178. Interlayer insulating
layer 160 functions as a dielectric. The capacitance is determined
depending upon the electric charges charged at capacitor 80 and the
voltages applied to the two capacitor electrode plates 158 and
178.
[0063] Switching thin film transistor 10 includes a switching
semiconductor layer 131, a switching gate electrode 152, a
switching source electrode 173, and a switching drain electrode
174. Driving thin film transistor 20 includes a driving
semiconductor layer 132, a driving gate electrode 155, a driving
source electrode 176, and a driving drain electrode 177.
[0064] Switching thin film transistor 10 is used as a switch for
selecting pixels to emit light. Switching gate electrode 152 is
connected to gate line 151. Switching source electrode 173 is
connected to data line 171. Switching drain electrode 174 is
separated from switching source electrode 173, and is connected to
one capacitor electrode plate 158.
[0065] Driving thin film transistor 20 applies a driving voltage to
pixel electrode 710 to excite organic emissive layer 720 of first
organic light emitting diode 70 in the selected pixel. Driving gate
electrode 155 is connected to capacitor electrode plate 158 which
is connected with switching drain electrode 174. Driving source
electrode 176 and the other capacitor electrode plate 178 are each
connected to common power line 172. Driving drain electrode 177 is
connected to pixel electrode 710 of organic light emitting diode 70
through a contact hole.
[0066] With the above structure, switching thin film transistor 10
is operated by a gate voltage applied to gate line 151, and
transmits a data voltage which is applied to data line 171 to
driving thin film transistor 20. A voltage corresponding to a
difference between a common voltage applied to driving thin film
transistor 20 from common power line 172 and the data voltage
transmitted from switching thin film transistor 10 is stored at
capacitor 80, and the current corresponding to the voltage stored
at capacitor 80 flows to organic light emitting diode 70 through
driving thin film transistor 20 to thereby excite organic light
emitting diode 70.
[0067] As shown in FIG. 3, encapsulation thin film 210 is formed on
organic light emitting element 70. Encapsulation thin film 210
includes a plurality of inorganic layers 211, 212, 213, and 214,
and a disparity barrier rib layer 220 is formed between the
inorganic layers 211, 212, 213, and 214.
[0068] Next, a second exemplary embodiment according to the
principles of the present invention will be described with
reference to FIG. 4.
[0069] As shown in FIG. 4, an organic light emitting diode (OLED)
display 102 constructed as the second exemplary embodiment includes
an encapsulation thin film 310 having a multi-layer structure in
which a plurality of inorganic layers 312 and 314 and a plurality
of organic layers 311 and 313 are alternately deposited. That is,
in encapsulation thin film 310, the plurality of inorganic layers
312 and 314 and the plurality of organic layers 311 and 313 are
alternately stacked.
[0070] Inorganic layers 312 and 314 may be made of a material
including at least one of Al.sub.2O.sub.3, TiO.sub.2, ZrO,
SiO.sub.2, AlON, AlN, SiON, Si.sub.3N.sub.4, ZnO, and
Ta.sub.2O.sub.5, and organics layers 311 and 313 may be made of a
material of a polymer group. Here, the polymer group material
includes an acryl-based resin, an epoxy group resin, polyimide, and
polyethylene.
[0071] In more detail, regarding to the operation of encapsulation
thin film 310, inorganic layers 312 and 314 has a relative high
density in order to firstly suppress the penetration of moisture
and oxygen. The penetration of most of the moisture and the oxygen
into organic light emitting element 70 is suppressed through
inorganic layers 312 and 314.
[0072] A minimal amount of moisture and oxygen passing through
inorganic layers 312 and 314 is secondly blocked by organic layers
311 and 313. The moisture blocking effect of organic barrier layers
311 and 314 is relatively less than that of inorganic barrier
layers 312 and 314. Organic barrier layers 311 and 313, however,
not only suppress moisture permeation but also perform as a buffer
layer that reduces stress between respective layers 311, 312, 313,
and 314 due to twisting of OLED display 102 between inorganic
layers 312 and 314. That is, when inorganic barrier layers 312 and
314 are deposited without having organic barrier layers 311 and 312
therebetween, stress occurs between inorganic barrier layers 312
and 314 due to twisting of OLED display 102, and the stress causes
damage to encapsulation thin film 310, thereby remarkably
deteriorating the moisture blocking function of thin film
encapsulation layer 210. As described, since organic barrier layers
311 and 313 suppress the moisture permeation and performs as the
buffer layer, encapsulation thin film layer 310 can stably prevent
permeation of moisture and oxygen.
[0073] Also, as shown in FIG. 4, encapsulation thin film 310
includes two inorganic layers 312 and 314 and two organic layers
311 and 313; the second exemplary embodiment is, however, not
limited thereto. Accordingly, the encapsulation thin film 310 may
be variously made of two or more inorganic layers and organic
layers if necessary. The arrangement order of the layers forming
encapsulation thin film 310 may also be variously changed.
[0074] Disparity barrier rib layer 320 is disposed between
inorganic layers 312 and 314 and organic layers 311 and 313. Also,
a filler layer 325 filling the space where disparity barrier rib
layer 320 is not formed is formed within the same layer as
disparity barrier rib layer 320. Organic light emitting diode
(OLED) display 102 according to the second exemplary embodiment is,
however, not limited thereto, and filler layer 325 may be
omitted.
[0075] Filler layer 325 has a relatively similar refractive index
to neighboring inorganic layer 312 and organic layer 313. That is;
the refractive index difference between inorganic layer 312 and
organic layer 313 and the air is more than the refractive index
difference between inorganic layer 312 and organic layer 313 and
filler 325. Accordingly, loss of the light passing through
encapsulation thin film 310 may be reduced.
[0076] Disparity barrier rib layer 320 may be made of one of the
organic layer and the inorganic layer including the light blocking
component. That is, disparity barrier rib layer 320 may be formed
of an organic material including a pigment such as carbon black or
titanium oxide, or an inorganic material including chromium,
chromium oxide, chromium nitride, or other metal oxides.
[0077] By this configuration, organic light emitting diode (OLED)
display 102 constructed as the second exemplary embodiment
according to the principles of the present invention may
effectively display three-dimensional images and simultaneously
reduce the overall thickness.
[0078] Further, encapsulation thin film 310 is formed by
alternately depositing inorganic layers 312 and 314 and organic
layers 311 and 313 such that encapsulation thin film 310 may be
prevented from being damaged due to the stress generated between
layers 311, 312, 313, and 314 of encapsulation thin film 310.
Accordingly, organic light emitting diode (OLED) display 102
according to the second exemplary embodiment further stably
protects the organic light emitting element 70.
[0079] Also, filler 325 filling the space where disparity barrier
rib layer 320 is not disposed is formed within the same layer as
disparity barrier rib layer 320 such that the loss of light passing
through encapsulation thin film 310 may be reduced.
[0080] Next, a third exemplary embodiment according to the
principles of the present invention will be described with
reference to FIG. 5.
[0081] As shown in FIG. 5, in an organic light emitting diode
(OLED) display 103 according to the third exemplary embodiment, a
disparity barrier rib layer 420 is formed on encapsulation thin
film 410. That is, encapsulation thin film 410 includes several
layers 411, 412, 413, and 414, and disparity barrier rib layer 420
is disposed on the highest and uppermost layer 414 separated
furthermost from organic light emitting element 70 among the
several layers 411, 412, 413, and 414 of encapsulation thin film
410.
[0082] In the third exemplary embodiment, encapsulation thin film
410 may be formed of a multi-layer structure in which a plurality
of inorganic layers are deposited, or a plurality of inorganic
layers and a plurality of organic layers are alternately
deposited.
[0083] By this configuration, organic light emitting diode (OLED)
display 103 according to the third exemplary embodiment may
effectively display three-dimensional images and simultaneously
reduce the entire thickness.
[0084] Also, encapsulation thin film 410 may be further stably
formed. That is, when disparity barrier rib layer 420 is formed
inside encapsulation thin film 410, the moisture blocking function
of encapsulation thin film 410 may be deteriorated due to disparity
barrier rib layer 420. When disparity barrier rib layer 420 is
formed on highest layer 414 of encapsulation thin film 410,
however, the moisture blocking function of encapsulation thin film
410 may be prevented from being deteriorated. Also, it is easy for
encapsulation thin film 410 and disparity barrier rib layer 420 to
be integrally formed such that the overall productivity of organic
light emitting diode (OLED) display 103 may be improved.
[0085] While this disclosure has been described in connection with
what is presently considered to be practical exemplary embodiments,
it is to be understood that the invention is not limited to the
disclosed embodiments, but, on the contrary, is intended to cover
various modifications and equivalent arrangements included within
the spirit and scope of the appended claims.
* * * * *